Fix configure.ac formatting
Currently, AC_ARG_[ENABLE|WITH] are used in multiple different ways. This change makes all their uses the same by following the style of the GNU manual:
- AC_ARG_ENABLE(foo) should only define $enable_foo
- Use the 2 argument form with a --enable_foo flag
- Use the 4 argument form with a --disable_foo flag
- Format all uses the same way
- Always compare using: test "x$enable_foo" = "xyes"
This makes the easier to debug, more readable, and shorter.
This formatting fix also revealed a bug (fix submitted seperately).
Edited by Joseph Richey